The debate continues on what features of oral performance are influenced by oral feedback. The present study tries to provide an answer to this question in an EFL context. To this end the effect of six different modes of oral feedback on the features of oral complexity and accuracy was investigated using data from 66 Iranian EFL learners who were selected conveniently from the Iran Language Institute. The participants were divided into experimental and control groups at two different levels of elementary and pre-intermediate. The experimental groups were presented with six different types of oral feedback modes (recasts, clarification requests, metalinguistic, praising, elicitation, and repetition) and at the end of the research they were tested by an in-class oral test to measure their complexity and accuracy (CA). To compare the participants’ oral features, a Wilcoxon Signed Rank Test and a Mann-Whitney U Test were run. The results indicated that complexity and accuracy significantly improved among the groups, moreover; there were significant differences in the post-tests between both elementary and pre-intermediate levels regarding CA. The results further indicated that Iranian learners of English would have fewer errors and would be more accurate when receiving oral feedback modes. The study highlights the complex relationship that exists between features of oral performance. The findings of the present study can have theoretical and practical implications for syllabus designers, teacher trainers, and testing researchers.